1. Field of the Invention
The present invention relates generally to small portable containers for storing, transporting and dispensing volatile flammable liquids such as gasoline, and to methods and devices for enhancing their fire combatant properties. Containers of this type are frequently referred to as safety cans.
2. Prior Art
Safety cans commonly in use have tubular filling and/or dispensing spouts closed either by threaded caps or by hinged spring closures. Threaded caps provide a firm closure, but are disadvantageous in that they are awkward to manipulate in normal use and are suitable only for situations where the use of the container is rather infrequent. While threaded caps may be provided with vent openings, such openings may not be sufficient to prevent bursting of the container under a rapid buildup of internal pressure.
For cans in frequent use, it has become accepted to provide their spouts with hinged, spring-biased closures which can be quickly opened either by direct manual contact or by an operating lever associated with the can's carrying handle. Such closures are normally biased closed in such a way that the closure can open slightly, in the manner of a relief valve, to relieve any buildup in internal pressure before it can reach a value threatening the integrity of the can.
The use of spring biased closures on safety cans may, in certain special situations, present a problem. If a safety can containing a flammable liquid such as a gasoline can should be surrounded by a local fire, the flammable contents of the can may boil and partially vaporize, causing a buildup in pressure within the can that is sufficient to cause the closure to lift slightly above the spout opening to relieve the pressure buildup. Once the closure has lifted, a mixture of flammable vapor and liquid is permitted to escape as a spray through an annular escape orifice formed between the spout opening and the closure. The spray pattern of this discharge of volatile material through the escape orifice is generally planar and extends radially outwardly from the axis of the spout. Due to the pressure at which the volatile mixture discharges and the restricted nature of the escape orifice, the spray may project radially outwardly for a distance of several feet from the can, and, when ignited, may tend to cause the local fire to spread.